1. Field of the Disclosure
The disclosure refers to a leak detector with a base appliance comprising a vacuum pump, a test gas detector and a control device, a sniffer probe connected with a housing of the base appliance through a hose, and a sub-housing containing a test leak device by which a supply of test gas is discharged in a controlled manner into a plug-in channel for the sniffer probe.
2. Discussion of the Background Art
Test gas leak detectors are used in detecting leaks in containers, conduits and other test items. A cavity of the test item is filled with a test gas, and the leak detector is used to determine the presence of test gas in the ambient air outside the test item. Helium often is the test gas of choice. The leak detector includes a test gas detector adapted to selectively determine the presence of the test gas. Moreover, it is intended to obtain information about the rate at which the test gas leaks from the leak found, or the size of the leak, respectively. For this purpose, the leak detector must be calibrated frequently. This is achieved with the use of a test leak. A test leak has a hole or a constriction with a known leakage value, the test leak being connected with a supply of pressurized test gas. For a calibration of a leak detector with a sniffer probe, the sniffer probe is moved into the proximity of the test leak, so that the leak indication can be adjusted.
In a leak detector described in WO 02/084246 A2, the test leak device is arranged in the housing of the base appliance below the base components, cooling air flowing through the housing from the bottom to the top.
DE 103 08 687 A1 describes a leak detector comprising a stationary base appliance and a test leak device provided in a sub-housing. The test leak device is connected with the main housing of the base appliance via a wire or a wireless radio link. It comprises a sub-housing in which a test gas supply is held in a test gas container. A data memory and a temperature sensor are attached to the sub-housing. The sub-housing has a plug-in channel for the insertion of a sniffer probe of the leak detector. Further, the sub-housing contains a membrane with a defined constriction through which the test gas escaping from the test gas supply flows at a controlled rate. The gas flows into a plug-in channel into which the sniffer probe is inserted. Thus, the sniffer probe draws the escaping test gas. Since the leakage rate is known, the leak detector can be calibrated. A light barrier extends across the plug-in channel of the pressure vessel. The light barrier forms a sensor for detecting the presence of the sniffer probe in the plug-in channel.
It is an object of the present disclosure to provide a leak detector, in which the test leak device is contained in a sub-housing so that the data communication and the accuracy of calibration are improved.